An electronic device for converting an optical signal from outside into an electric signal, for example, is provided with an electronic element having a light receiving portion as a functional portion. In a case where resin is present on an optical path of the optical signal in such an electronic device, the optical signal is attenuated. Besides that a black resin, which can adapt an electronic device to a lead-free reflow conditions by improving a humidity resistance of the electronic device, cannot be used on an optical path of an optical signal. In addition, as for an electronic device relating to an optical recording technology using a blue light for the optical signal, when an epoxy resin is used on an optical path, the epoxy resin on the optical path is degraded by the blue light and light transmittance of the epoxy resin is decreased. Thus some of such electronic devices are structured such that no resin is provided on an optical path, that is, a light receiving portion is exposed (Patent Document 1, for example). It is expected that an electronic device having an exposed functional portion can be applied to MEMS (Micro Electro-Mechanical Systems), a device in which a moving part of a functional element (electro-acoustic filter, for example) cannot be coated with resin, solid image sensing element for a camera, and the like.
Patent Document 1 discloses a semiconductor device having a protruding portion for preventing contamination of an exposed light receiving element. As to the semiconductor device disclosed in Patent Document 1, a semiconductor bare chip having a light receiving portion is mounted on a circuit board by flip chip attachment, a penetration hole is provided on the circuit board at a position corresponding to the light receiving element, and sealing resin is applied between the semiconductor bare chip and the circuit board. The frame-shaped protruding portion is provided around the penetration hole on the circuit board and the semiconductor bare chip is mounted in contact with the top of the protruding portion.    [Patent Document 1]    Japanese Patent Kokai Publication No. JP-P2003-68939A